well when you get into the lab the guys show up as enemy, but they still act like friends and you can go on as friends with them until you get outside with krugolov, at that point he pulls out a pistol and trys to kill you, and you can just put a bullet in his head andgo on with the mission as if the zombies killed krugolov...but you can still play the whole mission with lab x16 and the guy will do eveything like he's supposed to enemy or not.

Oh yeah one more thing, what if u join Freedom before you save Krugolov when his helicopter crashed in Wild Territoy??Will you still be able to do the Lab X16 quest???